Artificial arm and hand



Och 22 1946. c MQILLENHQUR 2,409,884

ARTIFICIAL ARM AND HAND Filed April 4,1945 5 Sheets-Sheet 1 I D. c. MOLLENHOUR I 2,409,884

ARTIFICIAL ARM AND HAND Filed April 4, 1945 I 5 $hee1zs-Sheet 2 Oct. 22, 1946. D, c. MOLLENHOUR 2,409,834

ARTIFICIAL ARM AND HAND Filed April 4, 1945 I 5 Sheets-Sheet 3 1946. D. c. MOLLENHOUR ,409,884

'ARTIFICIAL ARM AND HAND Filed Apfil 4, 1945 5 Sheets-Sheet 5 Patented Oct. 22, 1946 ARTIFICIAL ARM AND HAND Delbert Clark Mollenhour, Mentone, Ind., as-

signor to Franklin I. Saemann, New York,

Application April 4, 1945, Serial No. 586,505

8 Claims.

This invention relates to artificial arms and hands.

The invention relates particularly to an improvement on the original hands as illustrated in the patents to Henning, No, 1,981,698, of November 20, 1934, and No. 1,366,453, of January 25, 1921.

The invention furthermore relates to that type of artificial arm which may be correlated with a natural arm stump resulting from the amputation of the arm either above or below the elbow joint.

Finally the invention relates to the operation and mechanical means for such operation enabling the hand of such an-arm to be actuated by muscular movements of'the wearer to open and close the thumb and fingers of such an artificial hand.

One important object of the invention is to provide means constituting an improvement over the Henning patent above mentioned. In this Henning patent it is to be observed that the closing of the space between the thumb and fingers of the artificial hand is regulated by a step-by-step movement so that only certain definite positions of the thumb and finger portions of such a hand will be able to grasp firmly an object to be held by the hand. The present improvement relates to a mechanism whereby an infinite number of grasping positions may be obtained.

A second important object of the invention relates to the mechanism whereby the thumb and the fingers may be biased toward each other so that an infinite number of grasping positions may be obtained.

A third important object of the invention is to provide, in the hand-closing mechanism, a novel form of friction clutch adapted to enable the grip of the hand-closing mechanism to be adjusted to an infinite number of gripping positions.

A fourth important object of the invention is to provide a novel clutch arrangement for a rotary disc such as is used in connection with the movements of artificial hand members.

A fifth important object of the invention is to provide means whereby, without the use of a natural hand, the hand-gripping mechanism may be controlled.

With the above and other objects in View the invention consists in general of certain novel details of construction and combination of parts 0 shownin Figure 8.

hereinafter fully described, illustrated in the accompanying drawings and particularly claimed.

In the accompanying drawings, like characters of reference indicate like parts in the several views andi Fig. 1 is a face View of a person wearing one type of this artificial arm.

Fig. 2 is a View of the anterior surface of the hand used herewith, the view showing the thumb and fingers in separated position.

Fig. 3 is a perspective view of the lower part of the device showing the relation of the lower arm means and the hand.

Fig. 4 is a section substantially through the line 4-4 of Fig.1, the View being arrangedto show the novel mechanism within the body of the hand.

Fig. 5 is a plan View, part in section, disclosing the back of the hand and the fingers connected thereto together with the mechanism for operating the several parts.

' Fig. 6 is an enlarged view on the line 6-6 of Fig. 5.

Fig. '7 is an enlarged detail showing the manner of connection of a certain clock-work spring used herein, the view being somewhat diagrammatic, this View being a partial section on the line .'l'! of Fig. 5.

' Fig. 8 is a detail section on the line 88 of Fig. 5

Fig. 9 is an enlarged detail section on the line 9--9 of Fig. 5, with the pull cord omitted.

Fig. 10 is an elevational view showing in detail the arrangement at the right side of Fig. 9.

Fig. .11 is a detailview partly in elevation and partly in section on the line I I| I of Fig. 9,da cer-. tain cover plate shown in Fig. 10 being omitted and the view disclosing the ratchet parts in posi-.

tion to stop rotation, in one direction, of a certain disc used herewith.

Fig. 12 is a view similar to Fig. 11 with the above-mentioned ratchet parts in position to allow free rotation of said disc.

Fig. 13 is a view similar to Fig. 10 but showing a modified form of the clutch.

Fig. 14 is a side view of the construction shown in Fig. 13.

Fig. 15 is a view similar to Fig. 11 but with the clutch modification of Fig. 13.

Fig. 1c is a modification of the locking bolt In the embodiment of the invention here shown an original arm has been illustrated capable of use whether the entire arm has been amputated above or below the elbow joint.

Obviously the particular construction by means of which this artificial arm is fitted on what remains of the wearers artificial arm after amputation is variable to a wide degree. Consequently, so far as the application of the artificial arm to the remnant of the natural arm is concerned a wide variety of details in proportion may exist. The invention as herein described is therefore to be considered as broad enough" to' include its ap plication to an arm amputated in=any location from the wrist to the shoulder joint.

As shown in Fig. 1 the novel features of the: invention are comprised between an upper arm section A, a lower arm section B, andahand section C.

Since the hand section is common to both an upper and a lower arm amputation it is deemed advisable first of all to describein particular this lower arm section. Now referring first of all to Fig. 5 it will be seen that there is indicated'in this figure what may be termed a cufi member wherein is centrally-located a screw 2| by means of which thiscufi member maybesorew-attached to a ring 22 on the lower endlof the lower arm portion B. This cuff member 2fl'supports a-hollow hand body 23 shaped to conform to the body of a human hand. This hollow member 23 extends forwardly to a location corresponding to the first joints of the fingers of such a hand asv indicated at 24. Thru the forward extremities of the sides of the'member 23' passes a bolt 25 which is provided at one end'with a kerfed head 26 foractuation by a screw driver and. at its further end is provided with a threaded extremity. 21. The side walls of the member 23 are respectively arranged to receive the head 2'! and threaded to receive 4 the head 26 and the. threaded endlzl. This bolt forms a-rocker pin onwhich-thefour fingers of a hand may rock. Mountedo'n this bolt is a tubular sleeve28, having bushings 2811' at itsends engaging on the bolt. Fixed onthesleeve 28 is a series of arms 29 constituting. the skeletalsu-pports of the finger portion of the hand. These skeletalsupports and thesleeve 28 are surrounded and embedded in a rubber or plastic involvement 30 shapedand formed; as shown particularly in Figs. 2, 3' and.4 to represent the fingers of a human hand and the base'of these fingers at the first joint. Arrangement is such that this sleeve and the finger involvement coveredby' the levers 29 may rock on the pivot screw orpin 25.

Extending laterally throughthe handbody 23 is a shaft 3| which is supported at one end in a bearing lug 32' at thumb side, preferably, of the body 23. This shaft 3| does not extend entirely through the body 23 but is supported at the end interior of said body by a bearing 33 secured to the interior face of the body 23- by screws 34; In alinement'with the shaft 3|, on the side opposite the b'eari'ng 32, is an opening 35" whereth-ru a-commonclock key maybe insertedto engage the angular head 35 on the shaft 3|. By this means the shaft 3| may be rotated. Mounted on the shaft3| is a discorwheel 31 where'- from projects a pin38; this'pin' being near'the periphery of said wheel 31. Connected'to the pin 38 is'one end of a clockspring 39which'ha's' its remaining end wound around the shaft 3| arid operatively connected thereto by the usual-pin 4a. This clock-spring, as shown Fig. 7 is so wound that it tends torotate-the disc or wheel 31 in the direction of the arrow Xsliownfihi-Ei'gi 4. Obviously the more the shaft 3| is rotated in the direction of the arrow the greater will be the tendency of the spring to rotate the disc in the same direction. Now the shaft 3| has one or more transverse openings 4| there-thru and the bearing 33 has an opening extending from its top down to the shaft 3| in alinement with the location of the openings 4|, these openings extending entirely through the shaft. A pin 42 may be inserted thru the opening in the bearing 33 and down thru one of the openings 4| of the shaft 3! so that after adjustment of the spring "the. shaft may be held in position and thus cause, toa greater or less degree-,rotation of the disc 3'! in the direction of said arrow.

.One of the skeletal supports 29, preferably that relating to the second finger, is extended rearwardly-toward the disc 32 as at 43 and is providedin" its rearwardly extending end with a slot 44' wherein is engaged a pin 45 projecting laterally from thedisc or wheel 31. Under these circumstancesrotation of the disc 37 in one direction willrock' the fingers of the device upwardly; of the hand and, in another direction, will rock such fingers downwardly.

The forward part of the body is provided with an opening 46'and thru the body sides atthis opening extends a pivot screw 41 similar tothe arrangement of the screw'25. On this screw 41 is rotatably mounted a -sleeve 48 having a forwardly projectingarm 49 representing the skeleton of the thumb of the device and coveredby rubber or other elastic material 5!] representing the contour of that thumb. Extending rearwardly from the sleeve-48-isanarm5| having a pivot 52 atits upper end andto this pivot is connected one end of a link 53 extending to apin- 54 fixed in the disc 3'! adjacent its periphery. The rotation of the disc 31, Withthis 0 arrangement, in the direction of the arrows biases the free end of the thumb downwardly and at the same time biases the free ends of the fingers upwardly. The disc 3'! is grooved'as at'55-and is provided adjacent its periphery with an opening 56 communicating with the groove by an opening 51. A pull cord 58 extends over the anterior or back portion of the groove down through the opening "5! and is provided with-a knot 59 in the opening '55. The pull to beexerted' on this cord or wire 58 is in the direction of the arrow Y of Fig. l and isthus against the action of the clock-spring 35.

Mounted on the shaft 3| is a yoke 59 which is so positioned that it has a surfaceiifl closer 55 to the periphery of the disc 3? at its *upper end than at its lower end.- Between this yoke and the disc 31 is located a ball 6| which, in its upper position jams between the surface 60 and the groove 55 as shown clearly in Fig. 9. In its 60 lower position this ballis loose between thesurface 60 and the bottomof the groove 55$ .In order. to control the position of this-ballthere is mounted on the yoke a lever 62' of. generally U-shape having a finger 63 projecting downwardly between the walls of the yoke and engaging on the top of the ball 6|. Referringnow to'Figs. 11 and 12 it will be s'eenitliat' this lever 62 in one position pushes the ball downwardly (Fig. 11) while in another. position allows the ball. to rise upwardly. A coiled compression spring 64 is heldin the rear. end... of: the: yoke beneath the ball and has its terminalxendi 65 hooked? over the top of the yoke; Thissprihg constantlyurges the ball. upwardly.. The lever 521st mountedon a. plate. 66 extending: laterally from the yoke and pivoted to the lower portion of this plate is a control arm 61 arranged, when in the position shown in Fig. 11 to push the ball downwardly but when arranged, as in Fig. 12 to permit the ball to rise upwardly. The levers 62 and 61 are covered by a cover plate 68 secured to the extension 66 by screw 69 and this cover plate has a lip turned inwardly so as to rest against the plate 66 and, when the lever 61 is in the position of Fig. 12, to constitute a stop therefor. This lever 61 projects thru a slot 1! in the wrist portion of the member 23 so that it may be contacted with a disc or other surface by movement of the operators arm and then may be shifted between the positions of Figs. 11 and 12. Obviously, when in the position shown in Fig. 11 the ball will not act as a pawl to stop movement of the disc 31 in the direction of the arrow but, when in the position of Fig. 12, the ballwill jam between the disc 31 and surface 69 and thus prevent rotation in the direction of the arrow X.

Under these circumstances it is obvious that this ball arrangement is such that it may look the disc 31 against rotation in a direction to open the space between the fingers and thumb at any one of an infinite number of points between the fully open position of such fingers and thumb and the fully closed position thereof. The arrangement thus forms an infinitely adjustable ratchet device for all positions within limits of the gripping operation of the hand.

In the form of the invention shown in Figs. 13, 14 and a shaft 3| has mounted thereon a yoke 83 quite similar to the yoke 59. Extending laterally from this yoke is a plate 84 and at the rear end of the yoke is a ball guide 95 wherein rests a ball 86 urged upwardly by spring 81, the action of these parts being like those of the analogous parts in the first form of clutch above described. The plate 84 carries a pivot 88 whereon is mounted the rear end of a lever 89 having a finger 99 for engagement with the ball 85. This lever 89 has a depending arm 9| provided with a notch 92. The plate 84 carries a second pivot 93 whereon is mounted a lever 94 having an operating end 95 for engagement by ones fingers or against some fixed object for the shifting of this lever. The lever 94 carries a lug 96 which fits in the notch 92 so that movement of the lever anticlockwise on the pivot 93 pushes the lever 89 downwardly. Securedto the plate 84 by a screw 91 is a cover plate 98 having an inturned lip 99. The lever 94 is free to oscillate slightly on the pin 89 and may move from the position shown in Fig. 14 laterally to engage, in a certain position such as shown in Fig. 15, behind the lip 99 so that the end of this lip forms a stop.

Under normal clutching position as shown in Fig. 13 the disc or wheel 3'! is free to turn in clockwise direction of Fig. 14 but is locked by the ball against turning in anticlockwise direction. If it be now desired to release the disc to permit its turning to some extent in anticlockwise direction the lever 94 is moved to force the ball downwardly, thus releasing the disc 9! which is allowed to open as much as may be desired and is again caught upon release of the lever 94 from movement by the ball 85. At times it is desirable to have entire control of the thumb by the pull-cord 58 and in this case the lever 94 is moved in anticlockwise direction until it reaches the position shown in Fig. 15 for engagement behind the lip 99. By this means the cuff or ring has extending upwardly a pair of,

straps l2 enclosing a leather or other suitable socket member 13 to receive the stump of the arm. The straps are continued upwardly and at their upper ends are pivotally connected as at 14 to a similar pair of straps 15 carrying a cuff 16 which fits around the upper arm and the sides,

of which may be adjusted by means of a buckle and strap arrangement 11. This upper cuff care ries the supporting harness 18, only a part of which is here shown as the style of the harness and the arrangement of the straps thereof may be varied without departing from this invention.

The cord or wire 58 is connected by a coupling 19 to a pull cord 89 which extends around the back of the wearer, one or more guide loopsBl being provided on the arm engaging part of the apparatus. This extension cord 89 is connected as at 82 to the harness in such way that muscular movements of the wearer will serve to pull on the cord 89 and thus actuate the disc 31 in a direction counter to that shown by the arrow X. The result of this will be that the thumb and finger portions of the device will close toward each other and, depending on the extent of muscular movement this closure may be varied at will.

In Figure 16 the bolt 25 is shown drilled on the threaded end after insertion into the aluminum casting 23 and 24. A taper shape punch (not shown) is driven into the drilled hole thus forcing the outer threads 2'! into the threads of the aluminum casting, giving it a friction squeeze.

This step is taken to prevent the threaded hinge pin from wearing into the aluminum and thereby becoming loose and possibly causin the fingers to fall out from the palm casting. With this construction the hinge pin can be retained satisfactorily in the casting and still be removed for replacement. 1

What is claimed is:

1. In an artificial limb, a hand member having a hollow body, a finger portion and a thrumb portion, at least one of said portions being pivoted to the body to bias toward and from the other, spring actuated means in the body urging said pivotal portion to bias away from the other, said spring actuated means including a rotatable disc having a peripheral groove, a ball engageable in said groove, and a ball guide holding said ball and inclined to lie closer to the disc periphery at one end than at the other, the closer end of the guide being spaced from the disc a distance less than the diameter of the ball.

2. In an artificial limb, a hand member having a hollow body, a finger portion and a thumb portion, at least one of said portions being pivoted to the body to bias toward and from the other, spring actuated means in the body urging said pivotal portion to bias away from the other, said spring actuated means including a rotatable disc having a peripheral groove, a ball engageable in said groove, a ball guide holding said ball and inclined to lie closer to the disc periphery at one end than the other, the closer end of the guide being spaced from the disc a distance less than the diameter of the ball, and a spring in said guide urging said ball toward the end closer to the disc.

tion, at least oneof said portionsbeing pivoted to the body to bias toward andfrom the other,

spring actuated means in the body urging said pivotal portion to bias away from the other, said spring actuated means including a rotatable disc having a peripheral groove, a ball engageable in said groove, a ballguide holding said ball and inclined to lie closer to the disc periphery at one end than the other, the closer end of the guide being spaced from the disc a distance less than the diameter of the ball, a spring in said guide urging said'ball toward the end closer to the disc, a rock lever pivoted adjacentsaid ball guide and having one end bearing against said-ball op osite the ball actuating spring, and means to rock said lever on its pivot.

4. In an artificial limb, a hand member having a hollow body,- a finger portion and a thumb portion, at least one of said portions being pivoted to the body. to 'bias toward and from the other, spring actuated means in the body urging said pivotal portion to bias away from the other, said' spring actuated means including a rotatable disc having a. peripheral groove, a ball engageable in said groove, a ball guide holding said ball and inclined to .lie closer to thedisc periphery at one end than the other, the closer end-of-the guide being spaced from the disc a distance less thanthe diameter of the ball, a spring in said guide urging said ball toward the end closer to the disc, a rock lever pivoted adjacent saidballguide and having one end bearing against said ball opposite the ballac'tuating spring, and means to rock said lever on its pivot, said last meansbeing arranged to force said lever to free the ball from contact with said disc in one position and to hold said ball out of contact with'the disc in a second-position.

5. Inan artificial limb, a hand member having a hollow body, a. finger portion and a thumb por tion, at least one of said portions being pivoted to the body to biastoward and from the other, spring actuated means in the body urging said pivotal portion to bias away from theother, said spring actuated means including a rotatable disc having a peripheral groove, a ball engageable insaid groove, a ball guide holding said ball and inclined to lie closer to the disc periphery at one end thantheother, the closer endof the guide being spaced from the disc a distance less than the diameter of the ball, a springin said guide urgingsaidball-toward the end.closer tothe disc, a rock lever pivoted adjacent. said ball guide and having one endbearingagainst said ball opposite theballactuati-ng spring, and means to rock said lever, on itspivot, said lastv means comprising a latch lever pivoted parallel to saidrock lever and having onearm engaging the rock lever to move the samebetween position to force .the ball against said spring and position to permitthe ball to move under action by said spring.

6. In anartificial limb, a hand member having a hollow body, a finger portion and a thumb portion, at leastv one of said portions being pivoted tothe body to bias toward and from the other, spring actuated means in the body urging said pivotal portion to bias away from the other, said spring actuated, means including a rotatable disc having a peripheral groove, a ball engageable in said groove, a ball guide holding said ball and inclined to liecloser to the disc periphery atone end than the other, the closer end of the guide being spaced from the disc a distance less than the diameter of the ball, a spring in said guide urging, said ball toward the end closer to the disc, a rock lever pivoted adjacent said ball guide and having one end bearing against said ball oppos-ite the ball actuating spring, and means to rocksaid lever'on its pivot, said last means comprising a latch lever pivoted parallel to said rock lever and having one arm engaging the rock lever to move the same between position to force the ball against said spring and position to permit the ball to moveunder action by said spring, said latch lever being further arrangedto latch the rock leverin the first named position when moved in one direction.

'7. In an artificial limb, a hand member having a hollow body, a finger portion and a thumbspor tion, at least one of said portions being pivoted to' the body to bias toward and from the other, spring actuated means in the body urging said. pivotal portion to bias away from the other, said spring actuated means including a rotatable disc having,

a peripheral groove, a ball engageable in said groove, a ball guide holding said ball and inclined to lie closer to the disc periphery at one end than the other, the closer end of the guide being spaced from the disc a distance less than the diameter of the ball, a spring in. said guide urging said ball towardthe end closer to-the disc, a rock lever pivoted adjacent said ball guide and having one end bearing against said ball oppositethe ball actuating spring, and means to rock said lever on its pivot, said last means being arranged to force said, leverto 'free the ball from contact with said disc in one position and to hold said ball out of contact with the disc ina second position, said last means projecting through said hand body and operable from the exterior thereof.

8. In an artificial limb, a hand member having a hollow body, a finger portion and a thumb, portion, at least one of said portions being pivoted to the body to bias toward and from the other, spring actuated means in the body urging said pivotal portion to bias away from the, othensaid spring actuated means including a rotatable disc having a peripheral groove, a ball engageable in said groove, a ball guide holding said ball and inclined to lie closer to the discperiphery at one end than the other, the closer end of the guide being spaced from the, disc a distance less than the diameter of the ball, a springin said guide urging said ball toward the end closer to the disc, arock lever pivoted adjacent said ball guide andhaving one end bearingagainst said ball opposite the ball actuating spring, and means to rock said lever on its pivot, said last means comprising a latch lever pivoted parallel to said rock lever and having one arm engaging the rock lever to movethe same between position to force the ball against said spring and positionto permit the ball to move under action by said spring, said latch lever being further arranged to latch the rock lever in the first named position when moved in one direction, said latch lever projecting thru the wall, of the hand bod and operable from the exterior thereof.

DELBERT CLARK MOLLENHOUR. 

